RT Journal Article T1 On the Origin of Sugar Handedness: Facts, Hypotheses and Missing Links-A Review A1 Fernando Martínez, R. A1 Cuccia, Louis A. A1 Viedma Molero, Cristóbal A1 Cintas Moreno, Pedro AB By paraphrasing one of Kipling’s most amazing short stories (How the Leopard Got His Spots), this article could be entitled “How Sugars Became Homochiral”. Obviously, we have no answer to this still unsolved mystery, and this perspective simply brings recent models, experiments and hypotheses into the homochiral homogeneity of sugars on earth. We shall revisit the past and current understanding of sugar chirality in the context of prebiotic chemistry, with attention to recent developments and insights. Different scenarios and pathways will be discussed, from the widely known formose-type processes to less familiar ones, often viewed as unorthodox chemical routes. In particular, problems associated with the spontaneous generation of enantiomeric imbalances and the transfer of chirality will be tackled. As carbohydrates are essential components of all cellular systems, astrochemical and terrestrial observations suggest that saccharides originated from environmentally available feedstocks. Such substances would have been capable of sustaining autotrophic and heterotrophic mechanisms integrating nutrients, metabolism and the genome after compartmentalization. Recent findings likewise indicate that sugars’ enantiomeric bias may have emerged by a transfer of chirality mechanisms, rather than by deracemization of sugar backbones, yet providing an evolutionary advantage that fueled the cellular machinery. PB Springer SN 0169-6149 , eISSN: 1573-0875 YR 2022 FD 2022-07-07 LK https://hdl.handle.net/20.500.14352/72743 UL https://hdl.handle.net/20.500.14352/72743 LA eng NO Junta de Extremadura NO European Regional Development Fund (ERDF/FEDER) DS Docta Complutense RD 7 abr 2025